Studies on technological problems associated with the processing of cooked frozen prawns. Pt. 1. Preprocess storage conditions of raw material in relation to quality

The chemical and organoleptic properties of prawn held in ice for different days prior to cooking and the changes after freezing and subsequent storage were studied with three different species of prawn viz. Metapenaeus monoceros, Metapenaeus dobsoni and Parapeneopsis stylifera. The optimum period for which the prawn can be kept under ideal conditions of icing prior to cooking has been worked out.

Studies on the preparation of fish silage. 1. Effect of quality of raw material and type of acid

An experiment was undertaken in which silver bellies (Leiognathus splendens) of different quality were used to produce silages using different concentrations of hydrochloric acid and formic acid. The quality and storage life of the various preparations are reported. Silages which keep for at least 30 days can be produced from silver belly held for 3 or 12 hours at 28°C by: 1) reducing the pH by addition of hydrochloric acid; 2) adding 0.5% formic acid and reducing the pH to 3.5 with hydrochloric acid; or 3) adding 2.5% formic acid.

Effect of copper, cadmium and Cu.Cd mixture on amino acid content in the poslarvae of penaeid shrimp, Penaeus monodon and P. penicillatus

This study document effects of short-term (96h) sublethal levels of copper, cadmium and their mixture on the amino acid composition of postlarvae of the penaeid shrimp, P.monodon and P.penicillatus . All experimental conditions were kept constant, temperature between 25-27•C and salinity 21-22 ppt. The estimated LD50 for Cu was 200 ug/L, for Cd 177.5 ug/L and for Cu.Cd mixture 250ug/L. In P. penicillatus at the same concentration of each metal, there was significant reduction in amino acid content, which was 8.01% higher than the control. Almost similar reduction in some amino acids was observed in P.monodon. At the maximum concentration of 400 ug/L, cadmium caused higher reduction in amino acid composition than did copper. Thus, amino acid composition may be regarded as a sensitive biochemical indicator of Cu and Cd toxicity because of the effect of these metals on protein synthesis, a signal of physiological stress in marine organisms subjected to heavy metal pollution.

Observations on the wastage of raw material and recovery of meat in the prawn processing industry

The wastage of prawns due to spoilage in processing factories accounted to about 0-12% in 1974, 0-35% in 1975, 0-3% in 1976 and 0-4% in 1977. Spoilage increases with the time lag between catching and processing and also due to defective icing. The paper discusses the counts of whole prawns required for obtaining meat of specified size grades.

Chitosan as a water clarifying agent

Chitosan may be used to reduce the bacterial load of water. Material prepared according to the method of Radhakrishnan & Prahu described in Res. & Ind., 16(4), pp. 265, used in 1% solution in 1% acetic acid was added at 10 ppm level to contaminated water and allowed to stand for 45 min. Cultures of E. coli, Staphylococci and a mixture of the 2 were inoculated into ordinary and muddy water. Bacterial load was determined, and it is shown that chitosan has excellent qualities as a coagulant/water clarifying agent, especially for muddy waters or those contaminated with suspended matter or bacteria.

Suitability of tuna red meat for preparation of wafers

Studies to find out the suitability of tuna red meat for preparation of wafers have indicated that the red meat as such is not a good raw material for the production of wafers. The wafers obtained had poor organoleptic quality and characteristic tuna red meat flavour unacceptable to consumers. Attempts to prepare the wafers with the red meat mixed with the meat of barracuda in varying proportions showed that the mixture of red meat and barracuda meat in the ratio 1:3 gives a product having excellent physical properties and good swelling characteristics. The overall organoleptic quality of these wafers was very much comparable to the wafers produced from other quality fish. Increasing the proportion of red meat not only affects the overall appearance of the product but a1so imparts the red meat taste to the product.

Raw material supply to shrimp freezing plants: some significant aspects

The shrimp processing plants located at any particular place receive their raw material supplies from local and outside centres. The raw material received, the form in which it was received, the relative contribution by local and outside centres and the seasonal variation in the supplies were studied with respect to the shrimp processing plants located at three places - Cochin, Veraval and Kakinada.

Studies on the suitability of HDPE material for gill nets

The suitability of HDPE yarn and HDPE twine in place of nylon for gill nets has been studied. As regards total catch nylon gill net is found to be better than HDPE nets. However, statistical analysis of the catch in respect of quality fishes shows that HDPE yarn nets are equally efficient as nylon nets.

Biodiversity and production of bioactive material from cyanobacteria in Persian Gulf

In this project sampling was done from 9 stations in 3 depths during 5 seasons to separate, identify and examine the biodiversity of cyanobacteria. Another sampling also has been done to analyse all physical and physicochemical parameters, primary production and polluting agents such as heavy metals and oil hydrocarbons in water and sediments. Along with optimization of Oscillatoria to study the ability of producing natural substances, these cyanobacteria were analysed from the point of antimicrobial and mutagenic effects. To examine the relationships among analysed parameters, the regression test, analysis of varian and Post Hoc were used. As the result of this study 48 genus of cyanobacteria were pecognised among which 35.5% were croco ccales and 64.4% were Hermogonals. Oscillatoria was one of the Filamentous cyanobacteria which had antibacterial and mutagenic effects. The results of multicommunity consistency varians test, post Hoc and homogenous subsets show significant difference between biodiversity of cyanotbacteria in coral ecosystem, Mangrove and transite. The linear correlation coefficient between biodiversity of cyanobacteria and bioenvironmental agents were examined, but there was no continuous relation between these factors and biological biodiversity. In Surface layer there was a significant correlation coefficent at 0.048 and probability at 95% confidence interval. Also, the biodiversity is depended on oil pollution and heavy metals such as copper (Cu) and chromium (Cr).